Sprinkle the steak with salt to taste and rub in the pepper. Brown on all sides in the oil. Cook for thirty or forty minutes, to the desired doneness.
Transfer the steak to a warm serving platter and pour off the fat from the skillet. Add one tablespoon of the butter and the shallots to the skillet. Add the wine and stir to dissolve brown particles on the bottom of the pan. Cook until the wine is reduced to one-quarter cup.
Add the cognac, cook for one minute, and stir in the brown sauce. Remove the sauce from the heat, add the remaining butter, and swirl pan until butter melts. Add lemon juice and serve with the sliced steak.